Temozolomiade will be evaluated for safety, efficacy, maximum tolerated dose & pharmacokinetics in Glioblastoma patients experiencing first relapse. The drug will be given orally, once/day for 5 days, every 28 days. Pts will fast for 4hr before and 2hrs after each daily dose. Pharmacokinetics drawn on Day 1 Cycle 1. Patient will be drawn at baseline and 4 times post-dosing. Patients with last names A-M will have labs drawn at 1.5,2.5,3.5 & 4.0 hrs. Patients with last names N-Z will be drawn at 1.5,2.0,3.0 & 4.0 hrs.